Internal combustion engine



P 1963 J. D. STEVENSON 3,402,705

INTERNAL COMBUSTION ENGINE Filed Feb. 20, 1967 2 Sheets-Sheet 1 FIG I NVENT R 6% W252 Sept. 24, 1968 iNVENTORAL LLM 9mm United States Patent 3,402,705 INTERNAL COMBUSTION ENGINE John Donald Stevenson, Costa Mesa, Calif. {P.O. Box 104, Sedona, Ariz. 86336) Filed Feb. 20, 1967, Ser. No. 617,311 2 Claims. (Cl. 123119) ABSTRACT OF THE DISCLOSURE A piston reciprocable in a cylinder has a connecting rod connection with a rotatable crankshaft. The crankshaft has circular webs carrying the connecting rod journal. A vane partition reciprocable in a slotted cylindrical rot-or extends between the connecting rod and crankcase dividing the interior of the crankcase into two chambers mutually isolated by the vane, crankcase, crankshaft web, and connecting rod during a portion of each crankshaft revolution. One of the chambers is provided with valving means for the transfer of a charge to a firing chamber, the other chamber is provided with means for inducting the charge.

My invention relates to reciprocating piston machines in which the connecting rod, the crankshaft and the crankcase form important elements of an oscillating vane machine.

An object of my invention is the design, construction and arrangement of the components of an internal combustion reciprocating piston machine in such a manner as to increase air induction per cycle to an amount substantially in excess of the volumetric displacement of the piston.

It is another object of my invention to achieve the above mentioned increase in breathing capacity without the use of auxiliary machinery, without materially increasing the number of moving parts and without materially affecting the weight, physical size, efiiciency and cost of the machine.

For similar reciprocating piston machines the maximum power output is proportional to the volumetric displacement of the piston and the rotational speed. The maximum air induction in such machines is limited to that of the volume of the piston displacement multiplied by the number of such induction cycles per unit time. In the case of the two-cycle engine, such induction periods occur once each rotation whereas with the four-cycle engine such induction periods occur on alternate rotations.

In substantially all of the present day reciprocating piston machines a crankshaft and a connecting rod are used to transmit power to or away from the piston from outside the machine. Since a crankshaft, a connecting rod, and the structure surrounding these components is inherent in reciprocating piston machines, it would be desirable to have these components function in such a manner that they effectively increase the air induction capacity per cycle of a machine having a given piston volumetric displacement.

In crankcase scavenged two-cycle internal combustion engines, the volumetric displacement of the piston with respect to the crankcase induces the new charge for each cycle. In this type of reciprocating piston machine, no effort is made to make the volume of charge handled per cycle greater than the volumetric displacement of the reciprocating piston. In unsupercharged fourcycle internal combustion engines, the volumetric displacement of the iston with respect to the combustion chamber induces the charge for each firing cycle. My invention will allow a substantial increase in induction in either of these cases. ln accomplishing these and other objects, I have pro- 3,402,705 Patented Sept. 24, 1968 vided details of structure exemplary forms of which are illustrated in the accompanying drawings, wherein:

FIG. 1 is a longitudinal section of a single-cylinder internal combustion engine in a plane perpendicular to the axis of the crankshaft and through the axis of the cylinder.

FIG. 2 is an isometric partial cutaway view of the crankshaft, piston, vane and rotor assembly to better show the relationship of the parts.

In FIGS. 1 and 2, I have shown the essential elements of my invention. My invention consists of a cylinder 21 in which piston 24 reciprocates. The crankshaft 25, rotatably mounted within the crankcase 28, has fully circular webs 26. The peripheries of the webs are machined to allow no more than a close clearance in the crankcase 28. The crankshaft turns in a clockwise direction.

The connecting rod 29 is pivotally connected at the upper end to the piston 24, and at the lower end to the crankshaft 25. The connecting rod 29 is substantially as wide as the distance between the inner faces of the crankshaft webs. The side edges of the connecting rod 29 form a close clearance with respect to the adjacent or inner surfaces of the crankshaft webs 26. The connecting rod 29 has a circular crankpin end 32 which has no more than a close clearance with respect to the inner surface of the crankcase 28 during a portion of each revolution of the crankshaft 25. In addition, a rectangular piece of metal or plastic 27 hereinafter referred to as a vane is inserted between the crank webs 26. This vane 27 is substantially as wide as the distance bet-ween the inner faces of the crankshaft webs 26 and is pivoted on one end and secured on the other end as a sliding member within a rotor 31. The rotor may be on either end of the vane 27 but is shown here as inserted within a cylindrical cavity in the crankcase housing 28. The crankcase 28 is fitted to a close relationship with the rotor 31 and the vane 27.

Thus, there is formed partition means, including the connecting rods circular crankpin end 32, vane 27 and its pivot, inserted within rot-or 31. Said partition means divides the crankchamber or the interior of the crankcase into two mutually isolated compartments or chambers during a portion of each revolution of the crankshaft. One chamber 38, is on the left hand side of the connecting rods circular crankpin end 32 and vane 27, and one chamber 39, is on the right hand side of the connecting rods circular crankpin end 32 and vane 27.

The crank-case 28 is provided with a charge inlet port 35. In communication with the charge inlet port 35 is passage 19 which allows induction of air or air and fuel mixture from a fuel injection carburetion component. A transfer passage 37 extends from the crankcase compressor to suitable valving mechanism for final delivery to the combustion chamber.

Operation When the piston 24 is at the top of its stroke. the entire crank-chamber, or interior of the crankcase, is in communication with the interior of the cylinder below the piston and the charge inlet port 35. This condition exists during the downstroke of the piston until the crankpin end of the connecting rod 32 passes the crankcase port 35. At this point the crankpin end 32 of the connecting rod 29, vane 27 and rotor 31 divide the interior of the crankcase into two mutually isolated compartments. One chamber 38 is associated with the crankcase port 35 and the other chamber 39 is associated with the transfer passage 37. This condition is maintained until the crankshaft 25 connecting rod 29 and piston 24 reach a predetermined position.

It is apparent that during the downstroke of the piston, after the crankpin end of the connecting rod 32 has passed the crankcase port 35, the chamber 38 associated with the crankcase port 35 is continuously increasing in volume 3 a and the chamber 39 associated with transfer passage 37 is continuously decreasing in volume. The continuously changing volumes of the two chambers 38 and 39 produce the pumping or compressing action of the crankcase compressor.

The volume of induction is the sum of that due to the movement of the piston and that due to the pumping action in the crankchamber. In the case of the two-cycle engine, one such crankcase pump is desirable for each cylinder of the engine whereas with the four-cycle engine, one crankcase pump for each two cylinders is sufiicient. With either engine the delivery of the charge occur during the period near the bottom dead center position of the piston. During this time there is little piston movement therefore less back action against the compressor, allowing a more efficient scavenging and charging action.

I claim:

1. Apparatus of the class described consisting of a ylinder, a crankcase in communication with said cylinder, a piston reciprocable in said cylinder, a crankshaft rotatably mounted within said crankcase, partition means dividing the interior of the crankcase into two mutually isolated chambers during a portion of each revolution of the crankshaft, one of said chambers provided with valving means for the transfer of charge to a firing chamber, the other of said chambers provided with means for the induction of charge, said partition means including a connecting rod pivotally connected at one end to said piston and at the other end to said crankshaft.

2. Apparatus of the class described consisting of a cylinder, a crankcase in communication with said cylinder, a piston reciprocable in said cylinder, a crankshaft rotatably mounted within said crankcase, partition means dividing the interior of the crankcase into two mutually isolated chambers during a portion of each revolution of the crankshaft, one of said chambers provided with valving means for the transfer of charge to a firing chamber, the other of said chambers provided with means for the induction of charge, said partition means including a connecting rod pivotally connected at one end to said piston and at the oiher end to said crankshaft, a flat rectangular vane pivotally attached to said connecting rod, said vane reciprocable in a slotted cylindrical rotor, said rotor mounted in said crankcase, said crankshaft fitted with fully circular webs on each side of said connecting rod, said crankshaft Webs fitted in close communication circumferentially with said crankcase, said connecting rod substantially as wide as the spacing between the crankshaft webs, said vane having the same width as the said connecting rod.

References Cited UNITED STATES PATENTS WENDELL E. BURNS, Primary Examiner. 

